#include<bits/stdc++.h>
using namespace std;
int main()
{
    int n, x, y, rest;
    cin>>n>>x>>y;
    if (y%x == 0)
        rest = n - y/x;
    else
        rest = n - y/x - 1;

    if (rest <= 0)
        cout<<0<<endl;
    else
        cout<<rest<<endl;
}
